A solid material online analysis device and analysis method capable of switching optical paths

Abstract

The present invention discloses an online analysis device and method for solid materials with switchable optical paths, comprising a LIBS system, a switching module, a measurement chamber, and a signal collection module. The LIBS system utilizes its own laser to emit laser light, which contacts an object in the measurement chamber through a dichroic mirror in the switching module, generating plasma, which is then collected by the signal collection module. The measurement chamber includes a particle flow measurement chamber and a tablet measurement chamber. The switching module, located between the LIBS system and the measurement chamber, is used to switch the optical path formed by the LIBS system's laser light between the particle flow measurement chamber and the tablet measurement chamber, thereby enabling detection of both the particle flow and the sample tablet. The present invention is equipped with a switching module for switching the optical path, allowing the laser light to interact with the solid material particle flow or the tablet sample under the same conditions, generating plasma, thereby obtaining spectral information of the same sample in both states.

Description

Technical Field

[0001] The present invention relates to the technical field of material analysis, and in particular to an online analysis device and analysis method for solid materials with switchable optical paths. Background Art

[0002] Laser-induced breakdown spectroscopy (LIBS) is an atomic emission spectroscopic technique that uses a high-power pulsed laser to ablate the sample to be tested, forming a high-temperature plasma. The emission spectrum generated during the cooling of the high-temperature plasma is analyzed and processed to obtain information on the elemental composition and content of the object being analyzed. This technique has the advantages of being able to detect any form of medium, requiring little or no sample pretreatment, allowing for remote measurement, and enabling simultaneous and rapid detection of multiple elements. It has demonstrated potential for application and development in areas such as material composition monitoring and quality control in actual industrial production processes.

[0003] Currently, LIBS-based solid material composition detection, such as rapid coal analysis, primarily targets lump coal samples and pulverized coal pellets. Applying this measurement mode to online monitoring of coal quality entering a boiler's air-to-pulverized duct requires additional sample pretreatment and control systems, significantly impacting the reliability and real-time performance of the detection system in engineering applications. Many substances involved in actual industrial processes exist as particle flows. Therefore, implementing LIBS for online measurement of solid material particle flows will facilitate the development of simple and reliable analysis systems, providing the theoretical and practical basis for the technology's real-world application in online industrial testing. However, the volatility of particle flow samples hinders calibration of the detection system, making the direct application of LIBS for the measurement of solid material particle flows challenging. Summary of the Invention

[0004] The object of the present invention is to provide an online analysis device for solid materials with switchable optical paths, so as to solve the problems raised in the above-mentioned background technology.

[0005] In order to solve the above technical problems, the present invention provides the following technical solution: comprising a LIBS system, a switching module, a measurement chamber and a signal collection module;

[0006] The LIBS system uses its own laser to emit laser light, which contacts the object in the measurement room through the dichroic mirror in the switching module, generating plasma, which is then collected by the signal collection module.

[0007] The measuring chamber includes a particle flow measuring chamber and a tablet pressing measuring chamber;

[0008] The switching module is located between the LIBS system and the measurement chamber. It is used to switch the optical path formed by the laser of the LIBS system between the particle flow measurement chamber and the tablet measurement chamber, thereby realizing the detection of particle flow and sample tablet.

[0009] Preferably, the switching module includes an electric slider and a slide rail matched therewith, the slide rail is perpendicular to the central axis of the laser probe, and the electric slider moves linearly along the slide rail.

[0010] Preferably, two hollow channels are provided on the upper portion of the electric slider, and the hollow channels are used to connect to the signal collection module;

[0011] The hollow channel comprises a first channel and a second channel, and a 45-degree dichroic mirror is installed in both the first channel and the second channel.

[0012] Preferably, the distance between the switching module and the sample surface of the tablet measurement chamber is the same as the distance between the switching module and the center of the particle measurement chamber.

[0013] Preferably, the tableting measurement chamber is located at the bottom of the switching module and is connected to the first channel, and the particle flow measurement chamber is located at the rear of the switching module and is connected to the second channel.

[0014] Preferably, a rotating platform is installed at the bottom of the tablet measurement chamber, and the rotating platform rotates so that the laser irradiates different positions of the tablet sample.

[0015] Preferably, the filter screen is an annular structure, wherein the middle cover is arranged at the output port at the bottom of the bracket, and the water trough is arranged along the outer annular surface of the filter screen.

[0016] Preferably, the optical path of the LIBS system includes a laser, a laser high lens, a silicon bias detector, a switching module, a combined lens and a measurement chamber.

[0017] Preferably, the signal collection module includes a plano-convex lens, a fiber optic probe, an optical fiber, a spectrometer, a pulse generator, a No. 1 cable, and a No. 2 cable; the center of the plano-convex lens and the fiber optic probe are located directly on the same level, and the fiber optic probe is located at the focus of the plano-convex lens; the fiber optic probe is connected to the spectrometer via an optical fiber; the output end of the spectrometer is connected to a computer; one end of the pulse generator is connected to the spectrometer via a No. 1 cable, and is connected to the laser via a No. 2 cable.

[0018] Preferably, the laser emits laser light, and the laser energy information is collected into a computer;

[0019] A method for online analysis of solid materials with switchable optical paths comprises the following steps: combining images collected by a CCD to automatically focus a laser on the surface of a tablet within a tablet measurement chamber, generating plasma, transmitting the signal to a spectrometer via an optical fiber, and then outputting it to a computer;

[0020] Construct a quantitative analysis model for each characteristic index based on tablet spectral information;

[0021] The optical path of the laser is switched by an optical path switching device so that the laser is focused on the particle flow sample in the particle flow measurement chamber, generating plasma, whose signal is transmitted to the spectrometer through an optical fiber and then output to the computer;

[0022] The light emitted by the plasma, which carries the corresponding particle flow information, is transmitted to the spectrometer, and the output spectral response signal is collected into the computer;

[0023] In the computer, the obtained particle flow spectrum information is corrected and combined with the above model to achieve the measurement of the particle flow sample characteristic indicators.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention is equipped with a switching module for switching the optical path, so that the laser acts on the solid material particle flow or the tablet sample under the same conditions to generate plasma, thereby obtaining spectral information of the same sample in two states. According to the correlation between the two spectral information, a calibration model is established using the tablet spectral information, and the optical path is switched to obtain the particle flow spectral data for online detection, thereby solving the calibration problem of direct detection of particle flow samples. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2 Schematic diagram of the electric slider in the switching module of the present invention. DETAILED DESCRIPTION

[0028] For ease of use, an embodiment of the present invention provides an online analysis device for solid materials with switchable optical paths. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0029] This embodiment provides a solid material online analysis device and method with switchable optical path, referring to Figure 1-Figure 2 shown.

[0030] First, LIBS technology is used to measure solid material pellet samples and construct a quantitative analysis model for analytical indicators. Then, a switching device is used to switch the optical path to obtain real-time spectral information of the solid material particle flow. Combined with the spectral characteristics of the pellet sample, it is used to correct the spectral characteristics of the particle flow sample, thereby realizing online direct detection of the particle flow.

[0031] Specifically, a solid material online analysis device with switchable optical path includes the following steps:

[0032] a) The pulse laser emits laser light, which is then passed through an optical device into an energy detection device, where the laser energy information is collected and stored in a computer;

[0033] b) Combined with the image collected by the CCD, the laser is automatically focused on the tablet surface in the tablet measurement chamber to generate plasma, the signal of which is transmitted to the spectrometer via optical fiber and then output to the computer;

[0034] c) constructing a quantitative analysis model for each characteristic index based on the tableting spectrum information;

[0035] d) switching the optical path of the laser by an optical path switching device so that the laser is focused on the particle flow sample in the particle flow measurement chamber, generating plasma, the signal of which is transmitted to the spectrometer via an optical fiber and then output to a computer;

[0036] e) The light emitted by the plasma and the corresponding particle flow information is transmitted to the spectrometer, and the output spectral response signal is collected in a computer;

[0037] In the computer, the obtained particle flow spectrum information is corrected and combined with the above calibration model to achieve the measurement of the particle flow sample characteristic indicators.

[0038] The specific steps are as follows: the obtained particle flow spectrum is preprocessed using channel normalization and then input into a mixed quantitative model for compressed particle flow, constructed using a transfer learning algorithm based on compressed tablet spectra. This model incorporates both compressed tablet and particle flow spectral information. The TrAdaboost algorithm uses weight updates during an iterative process to extract information from the compressed tablet spectrum that is similar to the particle flow characteristics, thereby achieving information transfer from the compressed tablet to the particle flow spectrum and regression prediction of the particle flow components. When the particle flow spectrum is input, the model is able to measure the characteristic indicators of the particle flow sample.

[0039] Figure 1 The figure shows an online analysis device for solid materials with switchable optical paths provided by the present application, including a LIBS measurement system, a measurement chamber, a switching module, and a signal collection module.

[0040] As shown in the figure, the LIBS system consists of a laser 1, a laser high-power lens 2, and a silicon-biased detector 3. Laser 1 emits a pulsed laser beam with a wavelength of 1064nm and a beam diameter of 5mm. The silicon-biased detector 3 detects wavelengths in the range of 200-1100nm with a rise time of 1ns. Laser high-power lens 2 forms a 45° angle with the laser optical axis output by machine GAC 1, has a diameter of 25.4nm, and is coated with a 1047-1064nm anti-reflection coating.

[0041] After passing through the laser high lens 2, the laser enters the switching module. Figure 2 As shown, the switching module includes an electric slider a and a slide rail b that cooperates with it. The slide rail b is perpendicular to the central axis of the laser probe, and the electric slider a moves linearly along the slide rail b. The electric slider a is provided with two hollow channels, which are used to connect to the signal collection module;

[0042] The hollow channel includes a first channel 6 and a second channel 7. A 45° dichroic mirror is installed in each of the first channel 6 and the second channel 7, namely, dichroic mirror 4 and dichroic mirror 5.

[0043] Combine Figure 1 As shown, the first channel 6 and the second channel 7 are both connected to the signal collection module, the difference being that the first channel is connected to the tableting measurement chamber 9 below, and the second channel is connected to the particle flow measurement chamber 12 at the rear.

[0044] By switching the slider, the laser light emitted by the laser is switched between the tablet measurement chamber 9 and the particle measurement chamber 12. During the switching, the positions of the two measurement chambers remain unchanged. By sliding the slider, the laser light enters different channels. The first channel 6 corresponds to the tablet measurement chamber, and the second channel corresponds to the particle measurement chamber 12. Once the slider is switched to a specific position, the laser light can be switched to the corresponding measurement chamber.

[0045] Specifically, the dichroic mirror 4 forms an angle of 45° with the laser optical axis output by the laser. A long-wavelength dichroic mirror with a diameter of 25.4 nm is selected and installed in the first channel 6. For light with a wavelength range of 200-800 nm, the reflectivity reaches more than 90%, and for light with a wavelength range of 850-1200 nm, the transmittance reaches more than 90%. The dichroic mirror (4) can allow the laser beam to pass through the lens to reach the particle flow measurement chamber horizontally coaxial with the laser to act on the particle flow sample to generate plasma. At the same time, the plasma is reflected by the dichroic mirror 4 and then reflected by the reflector 13 to the plano-convex lens 14, enters the signal collection module, and is transmitted to the computer to obtain spectral information of the particle flow.

[0046] The combined lens 11 is coaxially assembled with a positive meniscus lens and a plano-convex lens, and is coaxially arranged with the tablet measurement chamber 9, perpendicular to the center position of the laser optical axis emitted by the laser, with the convex surface facing the dichroic mirror. The positive meniscus lens and the plano-convex lens have the same focal length of 100nm and a diameter of 25.4nm. The surface of the positive meniscus lens is coated with a 1050-1700nm anti-reflection film, and the surface of the plano-convex lens is equipped with a 1064nm anti-reflection film.

[0047] In addition, an electric rotating table 10 is installed at the bottom of the tablet measurement chamber 9. When the laser emits laser light and reaches the sample surface and completes the specified number of pulses, the electric rotating table 10 rotates a certain angle so that the laser hits different positions on the tablet surface.

[0048] The laser optical axis output by the dichroic mirror 5 is at an angle of 45 degrees. A short-wavelength dichroic mirror with a diameter of 25.4 nm is selected and installed in the second channel 7. For light with a wavelength range of 850-1100 nm, the reflectivity reaches more than 90%, and for light with a wavelength range of 200-800 nm, the transmittance reaches more than 90%. The dichroic mirror (5) can reflect the laser beam so that the laser reaches the surface of the tablet measurement chamber set perpendicular to the laser, excites the tablet sample to generate plasma, and at the same time, the plasma is reflected by the dichroic mirror 5 and then reflected by the reflector 13 to the plano-convex lens 14, enters the signal collection module, and is transmitted to the computer to obtain the spectrum information of the particle flow.

[0049] The combined lens 11 is coaxially assembled using a positive meniscus lens and a plano-convex lens, located at the same horizontal position as the center of the laser, with the convex surface facing the dichroic mirror. The positive meniscus lens and the plano-convex lens have the same focal length of 100nm and a diameter of 25.4nm. The surface of the positive meniscus lens is coated with a 1050-1700nm anti-reflection film, and the surface of the plano-convex lens is coated with a 1064nm anti-reflection film.

[0050] The particle flow measurement chamber 12 is sealedly connected to the sampling and delivery system at the top and bottom, and contains a channel inside to ensure that a stable and continuous particle flow sample passes through the center of the measurement chamber, which is located at the focus of the combined lens (11).

[0051] The center of the reflector 13 is perpendicular to the output laser optical axis of the laser and is at an angle of 45°. The diameter is 25.4nm. A broadband reflector is selected. The reflector divides the received light into two paths. One path is split into the collection module and enters the optical fiber probe and is transmitted to the spectrometer through the optical fiber. The other path is split into the camera module 22 and the surface conditions are captured in real time by the camera.

[0052] The center of the achromatic doublet lens 21 is perpendicular to the output laser optical axis of the laser, has a diameter of 25.4 nm, a focal length of 100 nm, and is coated with a 400-700 nm anti-reflection film on its surface.

[0053] Plano-convex lens 14 and reflector 13 are aligned horizontally, with the convex surface facing the spectrometer. Its diameter is 25.4 nm and its focal length is 50 nm. Fiber optic probe 15 is located at the focal point of plano-convex lens 14 and is connected to the spectrometer via optical fiber 16.

[0054] One end of the pulse generator 18 is connected to the spectrometer 17 via cable 19 and to the laser 1 via cable 20. The function of the pulse generator 18 is to set the delay between the laser pulse and the spectrum collected by the spectrometer.

[0055] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A solid material online analysis device with switchable optical path, characterized in that :Includes LIBS system, switching module, measurement room and signal collection module; The LIBS system uses its own laser to emit laser light, which contacts the object in the measurement room through the dichroic mirror in the switching module, generating plasma, which is then collected by the signal collection module. The measuring chamber includes a particle flow measuring chamber and a tablet pressing measuring chamber; The switching module is located between the LIBS system and the measurement chamber, and is used to switch the optical path formed by the laser of the LIBS system between the particle flow measurement chamber and the tablet measurement chamber, thereby realizing the detection of particle flow and sample tablet; The switching module includes an electric slider and a slide rail that cooperates with it. The slide rail is perpendicular to the central axis of the laser probe, and the electric slider moves linearly along the slide rail. There are two hollow channels on the upper part of the electric slider, which are used to connect to the signal collection module; The hollow channel comprises a first channel and a second channel, and a 45-degree dichroic mirror is installed in both the first channel and the second channel.

2. The solid material online analysis device with switchable optical path according to claim 1, characterized in that: The distance between the switching module and the sample surface of the tablet measurement chamber is the same as the distance between the switching module and the center of the particle measurement chamber.

3. The solid material online analysis device with switchable optical path according to claim 2, characterized in that: The tableting measurement chamber is located at the bottom of the switching module and is connected to the first channel. The particle flow measurement chamber is located at the rear of the switching module and is connected to the second channel.

4. The solid material online analysis device with switchable optical path according to claim 3, characterized in that: A rotating table is installed at the bottom of the tablet measurement chamber. When the rotating table rotates, the laser irradiates different positions of the tablet sample.

5. The solid material online analysis device with switchable optical path according to claim 4, characterized in that: The optical path of the LIBS system includes a laser, a laser high lens, a silicon biased detector, a switching module, a combined lens, and a measurement chamber.

6. The solid material online analysis device with switchable optical path according to claim 5, characterized in that: The signal collection module includes a plano-convex lens, a fiber optic probe, an optical fiber, a spectrometer, a pulse generator, a No. 1 cable, and a No. 2 cable; the center of the plano-convex lens and the fiber optic probe are located at the same level, and the fiber optic probe is located at the focus of the plano-convex lens; the fiber optic probe is connected to the spectrometer via an optical fiber; the output end of the spectrometer is connected to a computer; one end of the pulse generator is connected to the spectrometer via the No. 1 cable, and is connected to the laser via the No. 2 cable.

7. A method for online analysis of solid materials with switchable optical paths, characterized in that: An online analysis device for solid materials with a switchable optical path according to any one of claims 1 to 6 is provided, comprising the following steps: a laser emits laser light, and laser energy information is collected in a computer; Combined with the image collected by the CCD, the laser is automatically focused on the tablet surface in the tablet measurement chamber to generate plasma, and the signal is transmitted to the spectrometer through the optical fiber and then output to the computer; Construct a quantitative analysis model for each characteristic index based on tablet spectral information; The optical path of the laser is switched by an optical path switching device so that the laser is focused on the particle flow sample in the particle flow measurement chamber, generating plasma, whose signal is transmitted to the spectrometer through an optical fiber and then output to the computer; The light emitted by the plasma, which carries the corresponding particle flow information, is transmitted to the spectrometer, and the output spectral response signal is collected into the computer; In the computer, the obtained particle flow spectrum information is corrected and combined with the above model to achieve the measurement of the particle flow sample characteristic indicators.

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